Professor Grune is conducting an experiment on perceptions of the credibility of eyewitness testimony. While the study was in progress, a case of mistaken identity received wide publicity: A person who was on death row was exonerated because the key witness had mistakenly identified him as the murderer. Professor Grune found that his participants were less willing to believe an eyewitness after the case was publicized. His research was hampered by a ________ confound.
A) maturation
B) history
C) testing
D) measurement

Question

Quizplus · Accepted Answer

The case of mistaken identity receiving wide publicity is an example of a history confound in Professor Grune's study. This is because an external event (the publicity of the case) occurred during the study that could have influenced the participants' responses, thus making it difficult for Professor Grune to conclude that any changes in perception of eyewitness testimony were solely due to the manipulation of the independent variable within his study.

Professor Grune Is Conducting an Experiment on Perceptions of the Credibility